Hyperleukocytic actue leukaemia served as an acute and critical disease of the blood system,its fatality rate can be as high as 20%-30%,and the systemic treatment should be carried out immediately af-ter diagnosis.At present,a number of studies at home and abroad have confirmed that the patients with hyper-leukocytic acute leukemia can achieve a similar remission rate and prognosis as the patients with non-hyperleu-kocytic acute leukemia after effective leukocyte lowering pretreatment.This article discussed the aspects such as the mechanism of leukemia cytosis and leukocyte lowering pretreatment therapy,in order to provide a theoretical basis for the clinical diagnosis,treatment and research of this malignant hematological cancer.